1. Field of the Invention
This invention relates to a self-pumping hydropneumatic shock absorbing strut with internal level regulation, in particular for motor vehicles, with a work cylinder which is filled with oil and is under the pressure of at least one gas cushion which is located in at least one high pressure chamber and acts as a spring. The work cylinder is divided by a piston, which piston is carried on a hollow piston rod, into two work chambers, with a piston pump which is driven by the spring movements and transports oil from a low pressure chamber into the work chamber. The work chamber is connected to the high pressure chamber, and the pump cylinder of the piston pump is formed by the hollow piston rod, whereby there are valves between the work chamber and the high pressure chamber for the decompression and compression damping.
2. Background Information
In similar shock absorbing struts, as described in German Patent No. 14 30 536, for example, the piston which is fastened to a piston rod, divides the work cylinder into two work chambers, whereby the piston rod is realized so that it is hollow, thereby forming a piston pump, and a pump rod is inserted in the cavity of this piston rod. On the end surface of the work cylinder there is a solid base which holds the pump rod elastically, and whereby this base also contains damping valves for the decompression and compression damping. These valves are illustrated only schematically, without a more detailed illustration of the concrete construction or realization.